Published on July 30, 2021

Video Friday: Learn about the production and balance of thyroid hormones and how specific nutrients play a role in optimal thyroid function

Certain nutrients, such as iodine, selenium, zinc, B-vitamins, vitamin D, vitamin A and amino acids, are needed for optimal thyroid health and function. Other body systems are important for thyroid health including the gut, adrenals and the brain, and if they aren’t working optimally the thyroid will be negatively impacted.

Learn more about these nutrients and body systems needed to maintain healthy thyroid function by watching today’s informational video by Dr. Justin Marchegiani.

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After watching the video, be sure to make note of our added details below!

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Maintaining Healthy Thyroid Function

Here is a quick summary of what this video discusses, along with additional information and details from GrassrootsHealth:

  • The thyroid is a gland that produces, stores, and releases thyroid hormones, which are important to the function of many systems and organs, including the heart, brain, liver, kidneys and skin. Thyroid hormones help regulate vital functions, such as breathing, heart rate, muscle strength, menstrual cycles, body temperature, metabolism, and more.
  • Thyroid dysfunction is under-diagnosed with some population studies indicating that up to 10% of Americans may have thyroid dysfunction. Thyroid autoimmunity is often missed and should be ruled out.

Steps for Healthy Thyroid Hormone Production and the Nutrients Needed

1. The brain signals thyroid to make thyroid hormone by producing TSH (thyroid stimulating hormone)

  • TSH increases when thyroid hormones are decreased (telling the thyroid to make more)
  • TSH decreases when thyroid hormones are increased (telling the thyroid to make less)
  • Nutrients needed include vitamin A, zinc, B vitamins, and protein

2. The thyroid makes the thyroid hormone T4

  • T4 generation needs sufficient amounts of iodine, tyrosine, iron, B6, B2, B3, vitamin C, and vitamin D; Dr. Marchegiani suggests a vitamin D level between 70-100 ng/ml (175-250 nmol/L)
  • Note: it is very important to get enough selenium when supplementing with iodine

3. T4 is converted to T3

  • Approximately 20% of T4 is converted to T3 at the thyroid; the other 80% is converted peripherally with the majority at the liver and the rest in the gut and adrenals
  • Gut health is important, especially since gut issues can impede absorption of the nutrients needed
  • Conversion requires selenium and zinc, and needs healthy liver function (which can be hindered by high toxins, not enough antioxidants, and low selenium), as well as healthy gut function and bacteria
  • Healthy cortisol levels are also needed to maintain healthy thyroid hormone levels. In fact, high stress can increase reverse T3, which is inactive and blocks the actions of T3.

A study by Mirhosseini it al. found that vitamin D supplementation to target a level of at least 40 ng/ml (100 nmol/L) resulted in a significant reduction of TSH and the detection of hypothyroidism and subclinical hypothyroidism. This study found a 30% reduced risk of hypothyroidism and a 32% reduced risk of elevated anti-thyroid antibodies among participants whose vitamin D level was 50 ng/ml (125 nmol/L) or higher.

Of note, vitamin B12 status was also significantly associated with low thyroid function, and improving vitamin B12 status was shown to significantly increase thyroid hormones FT3 and FT4.

What nutrients might you be missing that could be preventing optimal thyroid function?

Make Sure You Are Getting Enough Vitamin D and Other Important Nutrients – Measure Your TSH as Well!

Having and maintaining healthy vitamin D levels and other nutrient levels can help improve your health now and for your future. Choose which to measure, such as your vitamin D, omega-3s, and essential minerals including magnesium and zinc, by creating your custom home test kit today. Take steps to improve the status of each of these measurements to benefit your overall health. You can also track your own intakes, symptoms and results to see what works best for YOU.

Enroll and test your levels today, learn what steps to take to improve your status of vitamin D (see below) and other nutrients and blood markers, and take action! By enrolling in the GrassrootsHealth projects, you are not only contributing valuable information to everyone, you are also gaining knowledge about how you could improve your own health through measuring and tracking your nutrient status, and educating yourself on how to improve it.

Help everyone Move Research into Practice with vitamin D and other nutrients! As a special birthday gift to everyone, in honor of the science, we have created a special scholarship fund for anyone to donate to that will go towards helping others participate. Your donation will allow anyone to get help with funding their participation when they need it.

Text-to-give: Text Daction to 44321 to add to our Scholarship Fund.

What Does it Take YOU to Get Your D to 40 ng/ml (100 nmol/L)?

Did you know your health could be greatly affected by making sure you have a vitamin D level of at least 40 ng/ml (100 nmol/L)? Help us help you.

STEP 1 - Do you know what your vitamin D level is? If not, be sure to test today to find out.

STEP 2 – Determine your target level. Are you at your target level? Experts recommend a level of at least 40-60 ng/ml (100-150 nmol/L).

STEP 3 – Need to boost your level? Use the D*calculator to see how much vitamin D it may take to reach your target. Opt for the Loading Dose for a quicker boost.

STEP 4 – Optimize how your body absorbs and utilizes vitamin D with co-nutrients and these simple steps.

STEP 5 – Re-Test! This is an important step to make sure you have reached your target level, and to ensure you are not taking too much! Re-testing after 3-4 months is recommended.

STEP 6 – Adjust, Repeat…

Give your immune system the nutrients it needs to support a healthy you and protect yourself from unnecessary diseases, especially COVID-19.


The first Randomized Controlled Trial on vitamin D and COVID-19 has shown a 96% lower risk of ICU admission for those receiving vitamin D (as 25(OH)D to quickly boost vitamin D blood levels) along with the standard treatment, compared to those receiving standard treatment alone.

These results support many previous observational studies showing a relationship between vitamin D levels and intake and COVID-19 severity.

Review the Latest Nutrient Research for COVID-19

GrassrootsHealth Nutrient Research Institute has launched the new Immune Boost project with the use of our myData-myAnswers nutrient health system that nearly 15,000 people are already using for their health. Specific markers that influence immune health are suggested for testing as part of this project including:

  • Vitamin D
  • Omega-3 Index
  • Essential elements magnesium, selenium, and zinc
  • hsCRP

Our goal is to demonstrate how one can use the Nutrient Research Model established by Dr. Robert Heaney to show the effect of vitamin D serum levels of at least 40 ng/ml (100 nmol/L) on risk reduction for all ethnicities in the population. Status and intake of other nutrients will also be analyzed for any type of relationship to immune status and symptom severity. Join the project today!

Please let us know if you're interested in helping sponsor this project.

CLICK HERE for updates and new information about the project.

Through GrassrootsHealth Nutrient Research Institute, you can also test your essential elements magnesium, copper, zinc and selenium, toxins such as lead, mercury and cadmium, as well as your omega-3 levels, inflammation levels and thyroid stimulating hormone (TSH) level. Find out your levels today! Log on to the test selection page (click the link below) to get your tests and see for yourself if your levels can be improved.

Make sure you track your results before and after, about every 6 months!

Click Here to Access the Test Page

How can I track my nutrient intake and levels over time?

To help you track your supplement use and nutrient levels, GrassrootsHealth has created the Personal Health Nutrient Decision System called

For each specific supplement, you can track what days you take it, how much, and many other details.  This will help you know your true supplemental intake and what patterns of use work for you to reach and maintain optimum nutrient levels. Check it out today!